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| | Direct memory access - Wikipedia, the free encyclopedia |
 | | DMA is an essential feature of all modern computers, as it allows devices to transfer data without subjecting the CPU to a heavy load. | | | For so-called "third party" DMA, as is normally used with the ISA bus, the transfer is performed by a DMA controller which is typically part of the motherboard chipset. | | | These symbols are generally seen on hardware schematics of computer systems with DMA functionality. |
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http://en.wikipedia.org/wiki/Direct_memory_access
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| | Define Direct Memory Access - a Whatis.com definition - see also: DMA |
| | Direct Memory Access (DMA) is a capability provided by some computer bus architectures that allows data to be sent directly from an attached device (such as a disk drive) to the memory on the computer's motherboard. | | | In the ISA bus standard, up to 16 megabytes of memory can be addressed for DMA. | | | The microprocessor is freed from involvement with the data transfer, thus speeding up overall computer operation. |
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http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci213903,00.html
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| | Direct Memory Access (DMA) Modes and Bus Mastering DMA |
| | DMA has been used on the PC for years over the ISA bus, for devices like sound cards and the floppy disk interface. | | | Problems with implementing bus mastering DMA on systems in the 1996 to 1998 time frame were numerous: issues with buggy drivers, software the didn't work properly, CD-ROM drives that wouldn't work with the drivers, and so on. | | | Bus-mastering DMA allows for the efficient transfer of data to and from the hard disk and system memory. |
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http://www.storagereview.com/guide2000/ref/hdd/if/ide/modesDMA.html
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| | How to Enable Direct Memory Access (DMA) |
| | Determine if DMA Is Enabled on Your Computer | | | The number associated with DMA indicates the direct memory access channel that the component or device uses to transfer data to and from memory. | | | First, determine if DMA is enabled on your computer. |
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http://support.microsoft.com/support/kb/articles/Q258/7/57.asp
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| | May 1992/Implementing Direct Memory Access (DMA) in C |
| | Direct Memory Access (DMA) transfers data from an I/O device to the computer's memory. | | | Direct Memory Access (DMA) has long been thought of as the best method to transfer data to and from a computer's memory. | | | DMA is the best method of transferring data since it is the most efficient method for transferring data and the least likely to cause a data overrun with a properly designed peripheral card. |
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http://www.tcnj.edu/~hernande/cujv5/html/10.05/bradley/bradley.htm
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| | Direct Memory Access (DMA) |
| | DMA (Direct Memory Access) is a way for I/O devices to bypass the CPU when accessing memory. | | | Thus the data flows from the I/O device to the CPU, and from the CPU to memory. | | | CPU signals memory that it is ready to write data to memory. |
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http://www.cs.umd.edu/class/sum2003/cmsc311/Notes/Memory/dma.html
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| | Direct Memory Access |
| | DMA makes large data transfers more efficient but can result in the CPU becoming idle if it can no longer access the instructions in the memory. | | | This is called direct memory access (DMA) and is usually between the hard disk and memory or video controller. | | | Overall though the time wasted in an idle state is less than the time required to transfer the data in byte sized chunks. |
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http://www.cit.gu.edu.au/teaching/1507CIT/Notes/book/book/node74.html
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| | Direct - Wikipedia, the free encyclopedia |
| | Direct memory access allows computers to permit access to system memory by certain hardware subsystems. | | | Direct connect refers to various methods of telecommunications and computer networking. | | | Direct access is a method of accessing data in a database. |
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http://en.wikipedia.org/wiki/Direct
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| | Direct memory access |
| | The processor informs the DMA controller that data is available (or is to be placed into) a block of memory locations starting at a certain address in memory. | | | In most mini- and mainframe computer systems, a great deal of input and output occurs between the disk system and the processor. | | | The order may be fixed by the order of connection (priority encoded), or it may be determined by some algorithm preloaded into the arbiter. |
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http://www.cs.mun.ca/~paul/cs3725/material/web/notes/node26.html
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| | Direct Memory Access (DMA) |
| | The device writes the byte of data to the memory, adds one to the pointer, and subtracts one from the counter. | | | So, suppose a device is doing a DMA transfer to memory. | | | Frequently (but not always), the Count register is in units of ``transfer size'' rather than bytes, as well (so if it were a word-size transfer, you'd specify how many words to transfer instead of how many bytes). |
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http://www.cs.nmsu.edu/~pfeiffer/classes/473/notes/dma.html
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| | IRQ, DMA and Addresses -Interrupt Requests, Direct Memory Access |
| | It is a memory location used by the device for interfacing with the computer. | | | This is used to allow transfer of data from one place to another in the computer without having the processor do it. | | | This is often referred to as "fly-by" and provides a limitation in the sense that DMA can only move data between devices (I/O ports) and memory. |
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http://www.hildrum.com/IRQ1.htm
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| | 20.3: Direct Memory Access (DMA) |
| | Given the Von Neumann architecture of the computer, two memory accesses are needed to transfer a byte from memory into the CPU: one to read the instruction, and one to fetch the data operand. | | | Up to now, be it via polled or interrupt driven i/o, the data transmitted between the computer system's main memory and an I/O device was CPU driven and invariantly involved the following code structure expressed in pseudocode. | | | Given the proper information such as where the data is to be found, and its length, the DMAC can automatically transfer large chunks of data from the I/O device to memory (and vice-versa). |
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http://www.cs.mcgill.ca/~cs573/fall2002/notes/lec273/lecture20/20_3.htm
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| | Direct Memory Access (DMA) Channels |
| | Direct memory access (DMA) channels are system pathways used by many devices to transfer information directly to and from memory. | | | DMA channels are not nearly as "famous" as IRQs as system resources go. | | | DMAs are used most commonly today by floppy disk drives, tape drives and sound cards. |
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http://www.pcguide.com/ref/mbsys/res/dma/index-c.html
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| | direct memory access |
| | Because the processor is not involved in the transfer, DMA is usually fast. | | | A method of transferring information directly from a mass-storage device, such as a hard disk, into memory without the information passing through the processor. |
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http://www.coffeycountyks.org/Terms/2461HTML-789.html
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| | Eureka Technology - AMBA AHB Direct Memory Access (DMA) Controller IP core |
| | Once it is programmed, DMA can be started either by a hardwire input signal or under software control. | | | To transfer data from the I/O port to the AHB bus, data is inputted to the I/O port when DMA starts. | | | Multiple independent DMA channels with direct AHB bus interface. |
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http://www.eurekatech.com/products/arm/ep246.htm
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| | random-access memory definition of random-access memory in computing dictionary - by the Free Online Dictionary, ... |
| | Furthermore, memory referred to as RAM can usually be read and written equally quickly (approximately), in contrast to the various kinds of programmable read-only memory. | | | This is in contrast to, say, a magnetic disk, magnetic tape or a mercury delay line where it is very much quicker to access data sequentially because accessing a non-sequential location requires physical movement of the storage medium rather than just electronic switching. | | | In the 1970s magnetic core memory was used. |
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http://computing-dictionary.thefreedictionary.com/random-access+memory
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| | Solaris Developer Connection - Driver Development |
| | The memory object has to be locked (for example, the memory can't be claimed by other processes thus causing the data to be paged out) before it can be used as a DMA object. | | | field and is associated with a physical memory that has been locked down by the system. | | | Since the PCI specification is byte alignment, this field should be set to 1 for PCI devices. |
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http://developers.sun.com/solaris/developer/support/driver/wps/pci/html/DMA.doc.html
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| | RedTeam: Updated Advisory: FireWire/IEEE 1394 direct memory access - CAN-2004-1038 |
| | As usual, physical access to a computer usually implies the ability for compromise - however, with this new technique, merely plugging in a malicious FireWire client device with special software could be enough to compromise a target. | | | This access can be used to read arbitrary memory from a system connected via FireWire and also to modify arbitrary memory contents. | | | Firewire/1394 host adapters which comply to the OHCI specification allow remote devices to initiate direct DMA based memory access to the host computers main memory. |
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http://blogs.23.nu/RedTeam/stories/5252
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| | Direct Memory Access (DMA) and Interrupt Handling |
| | Many times software designers have to work with data structures that are shared with interrupts or DMA devices. | | | This means that a new DMA operation can be started in the middle of an instruction execution (Keep in mind that an instruction execution involves multiple bus cycles). | | | The impact of DMA on processor's internal cache is also covered. |
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http://www.eventhelix.com/RealtimeMantra/FaultHandling/dma_interrupt_handling.htm
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| | Enable DMA - How To Enable DMA in Windows XP - Direct Memory Access - Windows 98 |
| | When this DMA feature is enabled, it basically allows your Hard Drive and CD Rom Drive to transfer their information directly to and from memory without passing through the Microprocessor. | | | In short, when your disk drives use Direct Memory Access to access their information, this reduces the load placed upon your CPU and your system works faster. | | | For Windows XP, Direct Memory Access is not set for individual Hard Drives and CD Rom Drives as depicted above. |
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http://www.real-knowledge.com/dma.htm
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| | Embedded.com - Introduction to direct memory access |
| | DMA permits the peripheral, such as a UART, to transfer data directly to or from memory without having each byte (or word) handled by the processor. | | | Implementing direct memory access is straightforward, once you know how it works and how to configure your DMA controller. | | | When the address is not incremented, each data byte will be transferred to or from the same memory location. |
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http://www.embedded.com/showArticle.jhtml?articleID=15300200
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| | Pointers / Direct Memory Access |
| | As I said, you can't poke an actual address, as Windows manages the memory for you (and it could happen it allocates a block of virtual-memory in the hard-disk). | | | Currently I've using BBbanks to alloc/deallocate slabs of memory for various structures. | | | By creating a bank, you do allocate a block of memory. |
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http://www.blitzbasic.com/Community/posts.php?topic=24339
(383 words)
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| | Direct Memory Access (DMA) Channels and Descriptions |
| | A direct memory access (DMA) channel provides high speed data transfer between a peripheral device, such as a disk drive controller, and memory without intervention by the CPU. | | | Listed below are the DMA channels for the IBM PC and XT class machines and the IBM AT and above class machines. |
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http://support.microsoft.com/?kbid=104418
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| | Direct Memory Access |
| | DMA 2: floppy, may also be used for a tape | | | A disk controller could transfer several blocks of data from the disk to RAM and then issue an interrupt | | | The CPU can do other work at the same time as the DMA transfer |
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http://orca.st.usm.edu/~seyfarth/sysadm/sysadm-6-2-1-6.html
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| | Direct Memory Access - OneLook Dictionary Search |
| | Direct Memory Access : Free On-line Dictionary of Computing [home, info] | | | direct memory_access : Dictionary of Computing and Digital Media [home, info] | | | direct memory_access : Hutchinson Dictionary of Computers, Multimedia, and the Internet [home, info] |
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http://onelook.com/cgi-bin/cgiwrap/bware/dofind.cgi?word=Direct+Memory+Access
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| | Fujitsu Releases New 32-bit RISC Microcontroller, the MB91302 : FUJITSU |
| | This technology makes it possible to move data directly between an external device and a memory, without passing through the CPU, thereby doubling the data transfer rate. | | | This significantly increases data transfer speeds and simplifies circuit board design due to a smaller parts count, resulting in cost savings. | | | The MB91302 implements interfaces for SDRAM, SRAM, asynchronous ROM (EEPROM, mask ROM), flash memory, and fast cycle RAM (FCRAM). |
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http://www.fujitsu.com/global/news/pr/archives/month/2003/20030408-01.html
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| | Memory access - Tech Tips - Memory Access Violations |
| | Random Access Memory or RAM is a type of (An electronic memory device) In today's computers memory access is becoming very slow when compared to | | | Real Knowledge is the place where people can aquire true information regarding computer tips of all sorts, including Windows 98, Windows Millennium, | | | How To Enable Direct Memory Access (DMA) For Windows 98, Windows |
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http://cutesky.com/c/memory-access.html
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| | USENET News article: Re: VGA - direct memory access question |
| | May be freely uploaded by WWW viewers and similar programs. | | | You need to specify which memory map to access | | | IAP@psuvm.psu.edu (Kirk Hanawalt) writes: > > I'm trying to write a program (TurboC 2.0, IBM PS/2 Model 50 >with VGA adapter, HP LaserJet II) to dump a bitmap image of the >high resolution VGA screen to a LaserJet printer. |
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http://www.spinellis.gr/news/21.html
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| | About Direct Memory Access |
| | Today, DMA have grown to be one of the largest wholesalers of computer hardware in WA. | | | They are currently the top Microsoft (OEM) and Intel channel partners locally, and are tier one partners with Panasonic - the only in the state. | | | Danny brought to the company a wealth of experience within the IT Industry, specifically regarding the manufacture of component parts and pre-built systems which were then distributed worldwide. |
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http://www.dma.net.au/?action=about
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| | RDMA offers low overhead, high speed |
| | Remote Direct Memory Access (RDMA) is a network interface card (NIC) feature that lets one computer directly place information into the memory of another computer. | | | Traditional hardware and software architecture imposes a significant load on a server's CPU and memory because data must be copied between the kernel and application. | | | Free utility scans network and finds systems that need immediate attention- Diskeeper Corp |
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http://www.networkworld.com/news/tech/2003/0324tech.html
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| | Disk Direct Memory Access |
| | Disk performance can be increased by enabling DMA transfer on systems that support it since some Windows installations do not have disk DMA enabled by default. | | | This page has more detailed information on enabling or restoring DMA mode transfer on Windows XP. | | | Direct Memory Access (DMA) reduces processor (CPU) overhead by providing a data transfer mechanism that does not require CPU monitoring. |
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http://www.sbclub.org/fhc/systems/diskdma.htm
(125 words)
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| | Direct Memory Access - DMA |
| | Short for Direct Memory Access, DMA is the transferring of data from one storage device to memory to another device without using the CPU. | | | Also see: Bus mastering, Memory definitions, PIO, UDMA | | | Because DMA is freeing up the usage of the processor, DMA tends to be faster than PIO mode. |
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http://www.computerhope.com/jargon/d/dma.htm
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| | DMA - Direct Memory Access |
| | Once this is done, it generates an interrupt to signal the completion of the task. | | | Without it, the CPU would have to copy the data one register-full at a time, using up hundreds or even thousands of interrupts and possibly bringing a halt to the machine! | | | The DMA controller is a device which copies blocks of data at a time from one place to the other, without the intervention of the CPU. |
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http://home.lanet.lv/~sd70058/aboutos/node30.html
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| | [No title] |
| | In this example, field values were accessed via direct memory/pointer usage. | | | I remember that a few months ago you gave an example of an alternative way of populating the MemData object. | | | It was said that this is much faster compared to using field value properties. |
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http://www.devexpress.com/Support/KnowledgeBase/ShowArticle.xml?kbid=186
(192 words)
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| | Direct memory access controller (EP0328450B1) |
| | a programmable logic array part (22), a data transfer between the input/output device (51) and the memory device (52) being controlled by the microprograms of the microsequencer (21) in co-operation with said programmable logic part (22); | | | Each data transfer between the input/output device and the memory device is controlled by the microprograms of the microsequencer in cooperation with the programmable logic array part. | | | A direct memory access controller coupled to a system bus (38, 39) of a system including an input/output device (51) and a memory device (52), for controlling a data transfer by direct memory access, said direct memory access controller comprising : |
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http://www.delphion.com/details?pn=EP00328450B1
(243 words)
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| | Direct Memory Access |
| | For block transfers DMA is far more efficient than interrupt driven IO. | | | IO <--> Memory is controlled by DMA unit. | | | DMA unit issues read and write cycles and is in control of the bus. |
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http://www.cs.buffalo.edu/~bina/cse421/spring00/lec1/sld011.htm
(34 words)
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| | DMA - Direct Memory Access |
| | Typical devices could be a graphics card that may write and read to memory directly. | | | A Direct Memory Access device may access memory without passing messages through the CPU (Central Processing Unit). | | | This significantly increases the processing speed of the system. |
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http://www.mpirical.com/companion/Multi_Tech/DMA_Access.htm
(41 words)
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| | Direct Memory Access |
| | The second class is a set of wrapper functions for the Virtual DMA specification ( | | | A set of programs demonstrating the various functions supplied in the library is available for downloading. | | | Note that while these functions work well under 16-bit DOS, VDS services which automatically transfer data between the user's buffer and the VDS services' buffer always fail to successfully transfer the data under 32-bit DOS. |
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http://members.shaw.ca/lwhaynes/c/dma.html
(107 words)
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| | Amazon.com: Direct Memory Access, Vol. 2: Music: Informatik |
| | Within Direct Memory Access 2.0, there are so many things that go right for a band just finding the footing that would later lead it down paths that would further morph into Syntax and then into the quite-different Nymphomatik, not to mention the side project Din Fiv and its two releases. | | | After a time, the works grew into heavily voxed machines and electronic beats drumming away on all fronts of humanity, taking the forms of bands like Informatik and their initial release, Direct Memory Access 2.0. | | | The techno/electro/industrial copulation works well with the lyrical contents of the songs inside, and the almost growlingly dark machine of a voice speaking from its pulpit becomes yet another instrument, working to further refine the beats being produced. |
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http://www.amazon.com/exec/obidos/tg/detail/-/B000005OPC?v=glance
(795 words)
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| | Overstock.com, save up to 80% every day! |
| | Download music straight from your computer to the MP3 player or the SD memory card without any special software or drivers. | | | The compact MyMusix portable MP3 player plays MP3 and WMA formats and stores music using SD (Secure Digital) memory cards. | | | Uses Secure Digital memory card up to 2GB (SD card not included) |
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http://overstock.com/cgi-bin/d2.cgi?PAGE=PRODUCT&PROD_ID=287411&cid=64666&...
(352 words)
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| | DDJ > MAY93: DIRECT MEMORY ACCESS FROM PC FORTRANS |
| | Under these conditions, it has never been tolerable for user programs to access pure physical addresses, because they would then be able to interfere with other concurrent programs. | | | The Fortran language has traditionally been used on large systems where multiuser protection is an issue. | | | This article remedies that by describing how to perform direct memory access using some of the better-known PC Fortrans, including the Microsoft, Watcom, and Lahey compilers. |
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http://www.ddj.com/documents/s=1034/ddj9305i/9305i.htm
(782 words)
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| | Direct memory access |
| | It would be great if I could read and write to specific addresses in memory. | | | For example, the Springboard slot supports IO addressing to modules using addresses 0x28000000 and 0x29000000. | | | The Suggestion Board uses cookies to record your display preferences |
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http://www.caslsoft.com/suggestions/index.cgi?read=217
(193 words)
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| | Get the BIOS Date Via Direct Memory Access (Win 95/98) |
| | Using them, you can read data directly from memory. | | | More information: VB runtime libraries (msvbvm50(60).dll) allow direct access to a memory address. | | | Instructions: Copy the declarations and code below and paste directly into your VB project. |
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http://www.freevbcode.com/ShowCode.Asp?ID=795
(91 words)
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| | The Remote Direct Memory Access Consortium |
| | Initial members include Adaptec, Broadcom, Hwelett Packard, IBM, Intel, Microsoft and Network Appliance. | | | Specifications: The Remote Direct Memory Access Consortium is an open consortium developing specifications for remote direct memory access over TCP/IP. | | | These specifications are intended to help organizations meet increasing demands for networking bandwidth and speed that are currently growing faster than the processing power and memory bandwidth available to process networking traffic. |
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http://www.consortiuminfo.org/links/rdma.shtml
(115 words)
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| | Direct Memory Access - Compare Prices, Reviews and Buy at NexTag - Price - Review |
| | 4MP - 3x Optical Zoom - 3x Digital Zoom - SD/MMC Memory Card - 0 MB Installed Memory | | | Direct Memory Access - Compare Prices, Reviews and Buy at NexTag - Price - Review | | | related searches:access,buy direct,access 2003,access point,microsoft access,ms access,attic access,access upgrade,citrix access,access ladders,access 2002,access control,furniture direct,jet direct,sony direct,direct tv equipment,direct vent,buy direct mattress,direct injection,memory |
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http://www.nextag.com/direct-memory-access/search-html
(84 words)
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| | Direct Memory Access |
| | The control register can be set to enable and disable interrupts from the device like simple input and output devices. | | | A DMA device has a small number of registers which can be accessed as if they were part of the memory. |
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http://www.cs.bris.ac.uk/Teaching/Resources/COMS11200/pages/tour5/tsld024.htm
(41 words)
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| | Multiple port integrated DMA and interrupt controller and arbitrator (EP0204960B1) |
| | This invention relates to direct memory access controllers and to character interrupt mode controllers in general as utilized in systems where there is a main processor and its associated main memory to which external devices require access. | | | A multi-port communications controller system enabling a direct memory access and an interrupt driven access for a bus connected processor (5) and memory system (6, 7, 8) providing communications services, comprising: | | | Data transfer controller incorporating direct memory access channels and address mapped input/output windows |
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http://www.delphion.com/details?pn=EP00204960B1
(431 words)
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| | Workshop on Remote Direct Memory Access |
| | Workshop on Remote Direct Memory Access (RDMA): Applications, Implementations, and Technologies (RAIT 2004) | | | RDMA, along with direct access to the networking hardware, also provides a low overhead mechanism for achieving low latency, high-bandwidth communication. | | | Remote Direct Memory Access (RDMA) enables transfer of data across a network directly to and from application buffers without requiring any intermediate copies or buffers. |
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http://grail.sdsc.edu/cluster2004/RDMA2004Workshop.htm
(299 words)
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